DSmith

Can anyone tell me what the maf scalar tables are for and if I need to mess with them for any reason? I'm using the 165 ecm 6E.
Thanks for hte help.

11sORbust

THe maf tables is what the ECM uses to calculate fuel (and spark). THe stock tables match the stock sensor. If you pull the screens out or port the MAF, then the maf tables will need some work. Other than that, I wouldn't touch them much.

327_TPI_77_Maro

iTrader: (8)

I also never saw someone truly explain what the maf scalars do. I know that they are multplied by the table data. BUT if you look in Tunerpro, the Maf tables overlap -- the last row in table #1 is the first row in table 2, the last row in table 2 is the first row in table 3, etc. AND, in Tunerpro, there are slightly different values for these overlapping rows -- something's wrong there. I see that the AYPY bin I based my current tune on has a table 1 scalar of 17, and most of the other 350 bins use a 19 scalar. Tuner pro 3x does not actually work properly with the scalars, you have to manually edit them. However, once I do this, I won't intuitively know what to do with the table I just changed, since the change will not be reflected in the table data (I don't think).

By the way, I had to touch my MAF tables quite a bit to get my tune right. Since you can't easily edit base pulse width in 6E, the MAF tables provide an indirect way to change fueling.

11sORbust

I think the original poster is talking about the maf tables, in general. You might be confusing the topic. At any rate, you have valid questions. Might want to start a fresh topic

DSmith

I was talking about the Scalar table, I have already been messig with the maf tables but I do not have a WB o2 so I am really having a hard time getting it dialed in. I did notice that the MAF tables overlapped and to me that didn't seam right but then again I'm still learning.
Thanks for the info

Grumpy

Yes, the last entry and first entry of the next table should match. If there's too large of step, and/or under just the right conditions, you'll have a **sag** there.

The scalers purpose is to give each table as much resolution as possible. For proof, take and double the scaler, and cut the corresponding table entries in 1/2. It's been my experience that doing that dropped throttle response, and cost MPG. Thou, I could see where in some appls, it might actually help.

DSmith

Thanks guys. I'm still learning and it looks like I have a long way to go but I'm getting better.

Grim Reaper

You really need a WB to properly tune MAF Scalar Tables. Until WBs became common, adjusting MAF Scalar Tables was not recommended unless you had a LOT of experience. I personally would not touch MAF Scalar Tables unless I did have a Wideband.

11sORbust

IMO, I think it's very possible to recalibrate the maf tables w/o a wideband.....at least the lower tables. I did it with a good O2 sensor and used closed loop to guide the way. That was with a stock cam in a 406. I couldn't do that now because of the huge cam (I now have). Lower engine speeds now have conflicting readings between the NB and WB O2s. If the engine is mild then it's possible to dial in small areas like idle. Generally speaking, I totally agree. Must have a wideband to tune the maf tables!

Grim Reaper

I don't rely on the stock NB O2 sensor for anything anymore. The range of operation is just too great and too inconsistent. One moment the NB is causing the ECM to run rich in high 13s and later as lean as 17:1. The NB is just not reliable.

With a WB, we found tuning the MAF Scalar tables a snap and gave much more consistent results. We are looking at tuning completely in Open Loop just to see if it runs more consistently. The cam is a solid roller 248/256 @.050 with a 110* LSA. Some might call it a "biggish" cam. But we noticed the rich/lean variation in closed loop operation even when we ran the smaller hydraulic roller.

3.8TransAM

I have started to work with maf tables, both on 148(the TTA) and the 165(friends 88 GTA) and am still having some trouble exactly pinning down a good definitive way for tuning maf setups.

Everyone always asks about scalar tables and the like, but could someone actually share their tuning hints for the 165?

Yes. I read the posts and searched :-) But looking for the actual ways people tune their maf setup is kind of confusing, even in the stickies. Maybe I have all the map stuff from $8D beat too deep into my head.

Some care to share the tuning process of the scalar tables in this post?

later
Jeremy

11sORbust

I think there is one sure fire way. Log the calculated A/F ratio and actual A/F ratio. Then adjust the maf table entries in order to get the actual A/F to match the calculated. Provided the fuel pressure and injector constant(etc) is right, it should get you darn close.

3.8TransAM

Interesting take on that 11sorbust.

Can definitely see the logic to the madness in that aspect of it.

Basically how the TTA will be tuned with the lockers once the weather breaks around here and Bruce and I can get out and have some fun.

Have to get my friends GTA set up so I can datalog it using my wideband and make notes, sounds like something that could work really well realtime with the romulator when I get a hang of it.

later
Jeremy

scottydta

i by know means label myself as an expert on 6E tuning but would like to throw 2 cents in after 2 years and 500 burns later on a MAF setup using only a scanner and stock O2.

after about six months of using the MAF tables themselves and getting minimal decent results, put them back to stock settings and decided to fool with the scalers instead even though some people say not to touch them. within in a week had the tune dialed in and the TA was running stronger than it ever had. this is what i took from my experience:

-scalers adjust fuel globally over the entire range of that particular table

-raise it to richen and lower to lean it out (pretty obvious)

-scaler tables 1-6 affect MAF tables 1-6 respectfully to their numbers. changes to scaler 1 will adjust fuel globally for MAF table 1 etc.... ect.

-the MAF tables tell you where the computer is looking at different flow rates (grams a second). MAF table 1 flows from 1 to 23 grams, MAF table 2 flows from 23 to 47 grams etc.......watch the grams a second on your scanner at different throttle openings and load drops and you can figure out which MAF table you are in.

-MAF table 1 is your idle and minimal throttle table
-MAF table 2 & 3 are your part throttle cruising as well as slight tip in
-MAF table 4 is 1/2 to 3/4 throttle opening
-MAF 5 & 6 are PE and full throttle

-watch the scanner to see what grams a sec. you are flowing, check your BLM's at that flow rate, find the table that flows that gram a sec. then adjust the scaler accordingly.

-the first 3 to 4 entries on MAF table 1 will have to be raised or lowered(most likely lowered) on a cammed car. the scaler might be correct for minimal throttle, but the idle is most likely rich because of it. use the sniff test to verify changes.

-adjust certain points on MAF tables if you see a mysterious lean or rich point at a certain throttle position.

please chime in if i am off base or want to add or clarify my findings. this method worked for me and gave me a calm idle and unbelivable throttle resopnse and drivability. not to mention my MPG increased. AE, PE, and torque converter settings are a whole different story.

racermike

Good points on MAF tables. I use a DVOM to monitor MAF volts while adjusting tables. I don't know if it is right or wrong but it seems to help me get close to 128 BLMs all the way from idle to 3/4 throttle. Now I am working on accel. enrich.

jackballs529

Scotty,

Using 6E in tunerPro is funky when it comes to adjusting the scalers. When you use the scroll bar things get whacky. Do you manually change the number from say 17 to 18. Or are you using another program to tune?

scottydta

using tunerpro and i adjust the scalers using the slide bar. be careful when you adjust. just one or 2 slides up or down makes a HUGE difference. know your starting point. when in doubt cancel your changes and start over. some of the numbers will change to letters,(the way the code or program is written which is beyond me), just think of it as an increase or a decrease and not what the actual number or letter combo is.

D's89IROCZ

are all these scallers and whatnot ...the same in tunercat ?

327_TPI_77_Maro

iTrader: (8)

Scotty, I have heard on this board that Tunerpro 3.xx does not actually change the maf scalars in the .bin file when you use the sliders -- you have to change the code manually or with another program.

scottydta

i have never had a problem using the slider. just made changes to my stock 305 trans am bin. leaned it out slightly with the scaler tables with immediate results.

Rebuildman

Same question: I do not see any scaler tables in tunercat, I do however see MAF tables 1-6.

clippjr8

The scalers are not in tunercat, just in tunerpro. This is a good thread for people to learn on. There is alot of information just in these few post.

Scottydta, You are exactly right on your tuning method. I have used it numerous times and always nail the tune down in no time. I use the maf tables themselves, but the scalers should work just the same.

watch the scanner to see what grams a sec. you are flowing, check your BLM's at that flow rate, find the table that flows that gram a sec. then adjust the scaler accordingly.

This is the best information you could ask for on tuning the part throttle fueling on the 6E code. Good Job!

Grumpy

The scalers are used to generate as much resolution as possible.
You *can* set the scalers to 255, and tune the tables that way, well at least in the 31T code, but the resolution is miserable. Miserable, be a subjective term.

Sure you can change the scalers, and in the VE tables only use increments of 10, but rarely, if ever, will that lead to the best possible tune.

Datalogging, with a WB, and matching commanded to actual, has always worked best for me so far.

dimented24x7

iTrader: (2)

Im surprised they dont have them listed. TC is set up to allow the scalars automatically multiplied in with the MAF flow in the table to show the actual flow.

As far as the scalars go, its best to set them up so that the last raw values stored in each of the tables get as close to 255 as possible. Youll have to tweak the stored values to make sure the airflow represented there doesnt change. The car will run like puke at low loads if you just go 1:1. I used the scalar/table statagy for a little while before I came to my senses and just used one big 16 bit table. That scalar stuff is just another thing used by gm to save a little space and processing time.

JPrevost

Here's a little visual aid for you to try and understand why adjusting JUST the scalors is a bad idea. Well I shouldn't say bad, more like ah... trying to not give the engine what it wants.
Also, editing JUST the tables and not matching up the corners is not smooth. Always keep things in check. This is why I've been adjusting the tables first and only move the scalors when you've hit the max and need more room at the sacrifice of resolution. Talking about resolution, look at the slope of that of the scalors only modified table. Notice how it's multiplication really does a lot by decreasing your resolution at low air flow . It's a shame really. Very hard to get a stable idle with some of these MAF cars. The half-assed solution has always been to raise the min idle on an engine that could very well run at a lower idle speed. Kind of the anti- engineering approach to a problem. So take this for what it's bandwidth is worth.

dimented24x7

iTrader: (2)

The resolution isnt half bad. The first table is the one that suffers the most as it has half the resolution of the others, but even thats ok if its set up right. Most of the tables are better then what I have. I went with 1/16 of a gram as the min unit of airflow taht can be stored for ease of calcs. Works good enough for me. IMO, the limiting factor is probably the 8 bit A/D converter as the minimum delta voltage is ~.0195 volts. Thatll be around a 3-4% variance in fueling at low flows just from that alone.

dimented24x7

iTrader: (2)

I was looking at the tables again and the resolution declines the higher you go, but the flow is increasing so it sort of balances out. At around 6 grams/sec the error from the maf is about 3 orders of magnitude larger then the stored value in the stock table. Its still another 'just good enough' solution, though, and I agree that they probably could have done better.

Also, another thing I just noticed is that GM puts a default value in the table at 0 grams/sec. so the car starts with the maf unplugged. Didnt even think to do that myself